Cutting insert having a flat edge surface for supporting the insert in a tool holder

Abstract

A cutting insert is produced by form-pressing and sintering of powder. The insert comprises a top chip surface, a bottom surface, and at least one edge surface extending between the top and bottom surfaces. The edge surface includes at least one relief surface portion which intersects the top surface at an acute angle to form therewith a cutting edge. A grinding operation is performed on the edge surface, but only along a lower portion thereof disposed below the relief surface portion, i.e., only along an area which is to be placed against a locating surface of a machine tool during a cutting operation.

What is claimed is: 
     
       1. A cutting insert for chipbreaking machining, said insert comprising a pressed and sintered powder body having a top chip surface, a bottom surface, and at least one edge surface interconnecting said top chip surface to form therewith a cutting edge; said edge surface also intersecting said bottom surface; said edge surface including a recess having an upper end spaced below said cutting edge, and first and second sides extending downwardly from said upper end; a first insert-supporting surface portion extending from said first side of said recess in a direction away from said second side; a second insert-supporting surface portion extending from said second side of said recess in a direction away from said first side; each of said first and second insert-supporting surface portions being flat and coplanar and extending downwardly to said bottom surface; each of said first and second insert-supporting surface portions forming an identical acute angle with a plane of said top chip surface. 
     
     
       2. The cutting insert according to claim 1, wherein said recess has a length extending parallel to said cutting edge, said length being 25-35% of a combined length of said recess and said first and second insert-supporting surface portions as measured along said bottom surface. 
     
     
       3. The cutting insert according to claim 1, wherein said edge surface further includes at least one clearance surface disposed between said first and second insert-supporting surface portions and said cutting edge and forming a first acute angle with a plane of said top chip surface said first acute angle being larger than a second acute angle formed by each of said first and second insert-supporting surface portions with said plane. 
     
     
       4. The cutting insert according to claim 1, wherein said recess extends downwardly and intersects said bottom surface. 
     
     
       5. The cutting insert according to claim 1, wherein said edge surface comprises one of a plurality of identically configured edge surfaces of said insert; said edge surfaces intersecting to form corner portions of said insert. 
     
     
       6. The cutting insert according to claim 5, wherein there are four of said edge surfaces.